Big is a 1988 American fantasy comedy-drama film directed by Penny Marshall and stars Tom Hanks as Josh Baskin, an adolescent boy whose wish to be "big" transforms him physically into an adult. The film also stars Elizabeth Perkins, David Moscow, John Heard, and Robert Loggia, and was written by Gary Ross and Anne Spielberg. It was produced by Gracie Films and distributed by 20th Century Fox.

Upon release, Big was met with wide critical acclaim, particularly for Hanks' performance. It was a huge commercial success as well, grossing $151 million worldwide against a production budget of $18 million, and it proved to be pivotal to Hanks' career, establishing him as a major box-office draw as well as a critical favorite. The film received Academy Award nominations for Best Actor (Hanks) and Best Original Screenplay.